Working machines include steering apparatuses designed to provide reduced forces required to operate operational levers for operating clutches and the like. The steering apparatuses include electric motors, plungers, springs or mechanisms using leverage for reducing force required to operational levers. Such steering apparatuses have assist mechanisms including springs for reducing force required to operate operational levers, as disclosed in JP-U-55-129169.
FIG. 15 hereof illustrates the disclosed assist mechanism 201 with an operational member 204 in a non-operated state and in an operated state.
As shown in FIG. 15, the assist mechanism 201 is used in a working machine or transporting machine. The machine is arranged such that an output from an engine (not shown) is transmitted through a transmission and side clutches (only one shown) 202 to right and left crawler belts.
The assist mechanism 201 includes a first rod member 203 having one end connected to the side clutch 202, and a second rod member 205 having one end connected to the operational member 204. The assist mechanism 201 also includes a pivotal member 206 having one side connected to each of the first and second rod members 203, 205, an intermediate part supported on a shaft, and an opposite side connected to a bar-shaped member 207 movable between a extended position and a contracted position. The bar-shaped member 207 has its distal end supported on a shaft. The bar-shaped member 207 is urged towards the pivotal member 206 by a compression spring 208 disposed along the length of the bar-shaped member 207.
With the thus arranged assist mechanism 201, a force to operate the operational member 204 can be reduced. It is to be noted that the operational member 204 shown in part (b) of FIG. 15 is in a pulled position located a distance S away from a position shown in part (b) of FIG. 15.
The first and second rods 203, 205, the pivotal member 206, the bar-shaped member 207 and the compression spring 208 are required for connection of the operational member 204 to the side clutch 202. Since the side clutch 202 is provided at each side of the machine body, the first rod member 203, each of the second rod member 205, the pivotal member 206, the bar-shaped member 207 and the compression spring 208 is provided in pair. That is, the assist mechanism 201 undesirably requires the increased number of components. The increased number of the components undesirably occupies a larger space.